4.5 UART Mode Switch (PA9)

  • When the host MCU pulls the UART mode switch pin from low to high (rising edge), the RNBD350 module switches to Data mode.
  • When the host MCU pulls the UART mode switch pin from high to low (falling edge), the RNBD350 module switches to Command mode.
  • When the host MCU uses the RN command to switch the mode, the host MCU keeps the UART mode switch pin to the original setting.
Note:
  • By default, the UART mode switch functionality is not assigned to the PA9 pin. The user can enable this feature using the SR,<hex16> command, for example, SR,0002. For more details, refer to Set Application Options.
  • If using PA9 for GPIO, do not enable pull-up or pull-down: use external resistors.